SBAS999A June   2019  – January 2021 ADS125H01

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Timing Diagrams
    9. 7.9 Typical Characteristics
  8. 8 Parameter Measurement Information
    1. 8.1 Noise Performance
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 Input Voltage Range
      2. 9.3.2 Analog Inputs (AINP, AINN)
        1. 9.3.2.1 ESD Diodes
        2. 9.3.2.2 Input Switch
      3. 9.3.3 Programmable Gain Amplifier (PGA)
        1. 9.3.3.1 PGA Operating Range
        2. 9.3.3.2 PGA Monitors
      4. 9.3.4 Reference Voltage
        1. 9.3.4.1 Reference Monitor
      5. 9.3.5 ADC Modulator
      6. 9.3.6 Digital Filter
        1. 9.3.6.1 Sinc Filter Mode
          1. 9.3.6.1.1 Sinc Filter Frequency Response
        2. 9.3.6.2 FIR Filter
        3. 9.3.6.3 50-Hz and 60-Hz Normal-Mode Rejection
    4. 9.4 Device Functional Modes
      1. 9.4.1 Conversion Control
        1. 9.4.1.1 Continuous-Conversion Mode
        2. 9.4.1.2 Pulse-Conversion Mode
        3. 9.4.1.3 Conversion Latency
        4. 9.4.1.4 Start-Conversion Delay
      2. 9.4.2 Clock Mode
      3. 9.4.3 Reset
        1. 9.4.3.1 Power-On Reset
        2. 9.4.3.2 Reset by RESETPin
        3. 9.4.3.3 Reset by Command
      4. 9.4.4 Calibration
        1. 9.4.4.1 Offset and Full-Scale Calibration
          1. 9.4.4.1.1 Offset Calibration Registers
          2. 9.4.4.1.2 Full-Scale Calibration Registers
        2. 9.4.4.2 Offset Calibration Command (OFSCAL)
        3. 9.4.4.3 Full-Scale Calibration Command (GANCAL)
        4. 9.4.4.4 Calibration Command Procedure
        5. 9.4.4.5 User Calibration Procedure
    5. 9.5 Programming
      1. 9.5.1 Serial Interface
        1. 9.5.1.1 Chip-Select Pins (CS1 and CS2)
        2. 9.5.1.2 Serial Clock (SCLK)
        3. 9.5.1.3 Data Input (DIN)
        4. 9.5.1.4 Data Output/Data Ready (DOUT/DRDY)
      2. 9.5.2 Data Ready (DRDY)
        1. 9.5.2.1 DRDY in Continuous-Conversion Mode
        2. 9.5.2.2 DRDY in Pulse-Conversion Mode
        3. 9.5.2.3 Data Ready by Software Polling
      3. 9.5.3 Conversion Data
        1. 9.5.3.1 Status Byte (STATUS0)
        2. 9.5.3.2 Conversion Data Format
      4. 9.5.4 Cyclic Redundancy Check (CRC)
      5. 9.5.5 Commands
        1. 9.5.5.1  General Command Format
        2. 9.5.5.2  NOP Command
        3. 9.5.5.3  RESET Command
        4. 9.5.5.4  START Command
        5. 9.5.5.5  STOP Command
        6. 9.5.5.6  RDATA Command
        7. 9.5.5.7  OFSCAL Command
        8. 9.5.5.8  GANCAL Command
        9. 9.5.5.9  RREG Command
        10. 9.5.5.10 WREG Command
    6. 9.6 Register Map
      1. 9.6.1  Device Identification (ID) Register (address = 00h) [reset = 4xh]
      2. 9.6.2  Main Status (STATUS0) Register (address = 01h) [reset = 01h]
      3. 9.6.3  Mode 0 (MODE0) Register (address = 02h) [reset = 24h]
      4. 9.6.4  Mode 1 (MODE1) Register (address = 03h) [reset = 01h]
      5. 9.6.5  Reserved (RESERVED) Register (address = 04h) [reset = 00h]
      6. 9.6.6  Mode 3 (MODE3) Register (address = 05h) [reset = 00h]
      7. 9.6.7  Reference Configuration (REF) Register (address = 06h) [reset = 05h]
      8. 9.6.8  Offset Calibration (OFCALx) Registers (address = 07h, 08h, 09h) [reset = 00h, 00h, 00h]
      9. 9.6.9  Full-Scale Calibration (FSCALx) Registers (address = 0Ah, 0Bh, 0Ch) [reset = 00h, 00h, 40h]
      10. 9.6.10 Reserved (RESERVED) Register (address = 0Dh) [reset = FFh]
      11. 9.6.11 Reserved (RESERVED) Register (address = 0Eh) [reset = 00h]
      12. 9.6.12 Reserved (RESERVED) Register (address = 0Fh) [reset = 00h]
      13. 9.6.13 MODE4 (MODE4) Register (address = 10h) [reset = 50h]
      14. 9.6.14 PGA Alarm (STATUS1) Register (address = 11h) [reset = xxh]
      15. 9.6.15 Status 2 (STATUS2) Register (address = 12h) [reset = 0xh]
  10. 10Application and Implementation
    1. 10.1 Application Information
      1. 10.1.1 Example to Determine the PGA Linear Operating Range
      2. 10.1.2 Input Signal Rate of Change (dV/dt)
      3. 10.1.3 Unused Inputs and Outputs
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
      3. 10.2.3 Application Curve
  11. 11Power Supply Recommendations
    1. 11.1 Power-Supply Decoupling
    2. 11.2 Analog Power-Supply Clamp
    3. 11.3 Power-Supply Sequencing
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Support Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.4.4.5 User Calibration Procedure

To user calibrate, apply the calibration voltage, acquire conversion data, and compute the calibration value. Write the computed value to the corresponding calibration registers. Before starting calibration, preset the offset and full-scale registers to 000000h and 400000h, respectively.

To offset calibrate, short the inputs to the system and average n number of the conversion data. Averaging conversion data reduces noise to increase calibration accuracy. Write the average value of the conversion data to the offset registers.

To gain calibrate using a full-scale calibration signal, temporarily reduce the full-scale register by 95% to avoid any output clipped codes (set FSCAL[2:0] to 3CCCCCh). Acquire n number of conversions and average the conversions to increase calibration accuracy. Equation 5 describes how to compute the full-scale calibration value:

Equation 5. Full-Scale Calibration Value = (Expected Code / Actual Code) × 400000h

where:

  • Expected code = 799998h using full-scale calibration signal and 95% precalibration scale factor